FBI Director Robert Mueller gestures at the U.S. Senate Judiciary Committee at an oversight hearing about the Federal Bureau of Investigation on Capitol Hill in Washington, June 19, 2013. REUTERS/Larry Downing (UNITED STATES – Tags: POLITICS CRIME LAW)

WASHINGTON (Reuters) – The United States uses drones for surveillance in some limited law enforcement situations, FBI Director Robert Mueller said on Wednesday, sparking additional debate about President Barack Obama‘s use of domestic surveillance.

The acknowledgement came in response to questions from U.S. senators who said they wanted to know more about the federal government‘s increasing use of unmanned aircraft.

“Yes,” Mueller said, adding that the use was in “a very, very minimal way and very seldom.”

Mueller did not go into detail, but the FBI later released a statement that said unmanned aircraft were used only to watch stationary subjects and to avoid serious risks to law enforcement agents. The Federal Aviation Administration approves each use, the statement said.

The FBI used a drone during a hostage-taking in Alabama this year after a gunman, Jimmy Lee Dykes, snatched a boy off a school bus and held him in an underground bunker, according to the statement.

DENVER — Colorado energy regulators on Monday proposed tighter rules for shutting down oil and gas pipelines after a fatal explosion blamed on natural gas leaking from a line that was thought to be out of service but was still connected to a well. The Colorado Oil and Gas Conservation Commission rules govern flow lines, which carry oil, gas and...